1. Field of the Invention
The present disclosure relates to an exposure technique, more particularly, relates to an exposure apparatus and an exposure system.
2. Description of the Related Art
As the panel display technique develops, a liquid crystal display has been applied widely in various devices, such as a computer, TV, a cell phone and a camera. Large dimension, high resolution and high quality have become a trend in the development of the liquid crystal display more and more. Large dimensional display products promote the development of high generation lines. Thus, the dimension of the mask of the exposure apparatus during processing of a substrate also becomes larger. It causes bending of the mask to become more and more apparent such that the problem that graphs formed on a color filter by performing a lithographic process with the mask have non-uniform dimensions becomes more and more severe and thus the quality of products may be degraded. Typically, the exposure apparatus is a proximity exposure apparatus.
The proximity exposure apparatus typically comprises a light source, an alignment system, a mask holder, a stage, a robot or the like. FIG. 1 is a schematic view showing a proximity exposure in a typical process for producing color filters. The proximity exposure apparatus as shown comprises a substrate stage 1, supporting legs 2, a glass substrate 3, a photo resist 4 and a mask 5. A distance between the mask 5 and the glass substrate 3 is in a range of several hundred micrometers. All of the supporting legs 2 have an identical height. During exposure, the large dimensional mask may be bent to some extent such that the distance between the mask 5 and the glass substrate 3 varies among various positions. In particular, an exposure distance at a central part of the glass substrate 3 is less than that at its edge part (i.e., G2<G1). Since the graph dimensions (CD) formed by exposing the photo resist material vary with the exposure distance in the proximity exposure, the graph dimension produced on the substrate are different, in particular, the graph dimension at the central part is less than that at the edge part (CD2<CD1), which degrades the quality of the display product.